Fire extinguisher head assembly



March 1.0, 1959 J; w. HOWARD FIRE EXTINGUISHER HEAD "ASSEMBLY File d Nov. 29, 1955 a um I Fia.3

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INVENTOR. JOHN W- HOWARD United States Pate 2,876,846 FIRE EXTINGUISHER HEAD ASSEMBLY John W. Howard, Altadena, Calif., assignor to General Pacific Corporation, a corporation of California Application November 29, 1955, Serial No. 549,608 4 Claims. (Cl. 169-31) This invention generally relates to a fire extinguisher head assembly and more particularly to an improved head assembly for a portable, tank type fire extinguisher, which in operation is adapted to discharge the contents of the extinguisher tank in response to release of pressurized gases therein.

The invention will be described with reference to dry chemical type fire extinguishers, although it will be appreciated that the primary features of this new fire extinguisher head assembly are equally applicable to extinguishers using gases or liquids.

As shown in Patent No. 2,710,658 issued June 14, 1955, for Fire Extinguisher, dry chemical type fire extinguishers usually comprise a head assembly which is connected in sealed relationship to an extinguisher tank. The head assembly is usually provided with an operating lever for actuating a plunger to in turn puncture a gas cylinder within the tank. The released gas then forces powder within the tank upwardly through a tube to the head assembly to thereafter be discharged through a communicating hose connection.

In the operation of present day dry chemical fire extinguishers, the operator must not only actuate the lever in the head assembly to effect the puncturing of the gas cylinder in the tank, but he must also operate a nozzle valve in the associated discharge hose in order to control and shut ofi the powder flow.

It is, therefore, a first object of the present invention to provide a head assembly for a fire extinguisher embodying improved plunger means, whereby the operating lever functions not only to release gases within the tank but also as a means of controlling and shutting ofi the discharge of the contents at any given time, thereby eliminating the necessity for a separate nozzle valve in the discharge hose.

Another problem in connection with present day dry chemical type extinguishers is the fact that the gas cartridge or cylinder of standard construction usually employs a threaded neck designed to be secured through the conventional tank opening into the head assembly. Vibration of the extinguisher under certain storage conditions as well as miscellaneous transport and handling of the extinguisher frequently results in a tendency for the cartridge to unthread itself from the head assembly with the result that it is displaced more than a critical, maximum distance from the plunger puncturing means. As a consequence, the plunger means may not be accurately positioned relative to the cylinder to effect proper puncturing thereof in response to actuation of the operating lever.

.Another object of the present invention, therefore, is to provide a means of securely and yet simply lockingthe 2 cartridge or cylinder at a given distance from the plunger means in addition to the threaded connection normally provided.

A further operating difiiculty in connection with conventional dry chemical type extinguishers is the fact that the puncturing tip of the plunger oftentimes has a tendency to become clogged as the puncture of the disc or other element in the cartridge is being efiected.

Consequently, a further object of the present invention is to provide a plunger means embodying a puncturing tip which substantially eliminates the possibility of clogging or the like during the puncturing operation.

These and other objects and advantages of the present invention are attained by providing a unit type head assembly as referred to in the above co-pending application, which includes a valve means associated with the plunger means and positioned to close olf the inner passage way in the head communicating between the discharge hose and the powdered tube inlet. This valve means is designed to close off the passage when the plunger is not being operated or is in its normal position. When the lever on the head assembly is actuated to in turn force the plunger down into puncturing position, the valve means associated therewith is adapted to open up the passage so as to permit powder to pass through the powder tube, the passage, and thereafter out through the discharge hose.

In order to prevent the cartridge or gas cylinder from working loose from its threaded connection to the head assembly, a locking means is provided in association with the head assembly and is adapted to engage the neck of the cartridge and securely maintain the cartridge in a given spaced relationship to the plunger means.

A further feature of the present invention is embodied in the actual structure of the puncturing end of the plunger. The improvement resides in the provision of a plurality of radially directed apertures communicating with the inner bore of the puncture tip and co-operating therewith to provide a substantially clog-free structure.

A better understanding of the present invention will be had by reference to the drawings, in which an illustrative embodiment is shown, and in which:

Figure l is a sectional view of the improved fire extinguisher head assembly of the present invention;

Figure 2 is a perspectiveview of a portion of the head assembly of Figure 1 illustrating the operation of the locking means; and,

Figure 3 is an enlarged view of the puncturing end of the plunger means of the head assembly of Figure 1.

There is shown in Figure 1 a fire extinguished head assembly including a head body 10, to which is pivotally connected an operating lever 11, as by a rivet 12. A stationary carrying handle 13 is also attached to the head body 10 by a rivet 14, the handle 13 acting as a means for balancing the extinguisher as it is moved from one place to another and also functioning as a gripping member when actuating the lever 11.

The lower portion of the head body 10 terminates in an annular shoulder 15 which is recessed so as to retain a double acting seal 16. The annular shoulder 15 is further shaped to accommodate an annular nut 17 which together with the seal 16 is provided to couple the head assembly in pressure tight connection with the conventional extinguisher tank opening.

The head body 10 further includes a downwardly extending hollow boss 18, provided with internal threads 19 for connection to a gas cartridge neck 20. The upper end of the boss 18 is closed off by a plug 21 secured within the head body 10 and provided with a central aperture 22.

Puncturing means in the form of a plunger 23 extends vertically through the head body 10 and is designed for sliding movement through the aperture 22 of the plug 21. The plunger 23 has coupled to it, valve means in the form of an O ring valve 24 adapted to seat as at 25 when the plunger 23' is in its normal position as shown in Figure 1. In order to assure proper seating of the valve 24 a spring 26 is disposed about the, upper periphery of the plunger 23 and is confined between the head body 10 and a drive pin 27 in the plunger so as to bias the plunger towards its normal upper position, thus assuring an adequate seating pressure for the valve 24. An ring 28 may be provided immediately below the spring 26 to seal the plunger 23 with respect to the head body It).

A powder tube 29 extends downwardly from a con nection within the head body to a lower area of the extinguisher tank (not shown) in a conventional manner. The powder tube 29 communicates at its upper end with an inlet chamber 30 within the head body 10 which in turn communicates with a discharge chamber 31 when the valve 24 is unseated, thereby forming an inner passage in the head body it). A discharge hose 32 is threadedly coupled into the head body 10 to form a sealed connection with the discharge chamber 31.

A gas tube 33 of a construction similar to that described in the above referred to co-pending application, communicates through an aperture 34 into the interior of the boss 13. The gas tube 33 serves as a means of directing the released gases from the gas cartridge down to the bottom portion of the extinguisher tank, after the puncturing plunger 23 has been actuated to break an appropriate seal in the threaded neck 20 of the cartridge.

As shown more clearly in the view of Figure 2, the threaded neck 20 of the gas cartridge is adapted to be threaded at 19 into the boss 18. Under certain storage or handling conditions, the neck 20 has a tendency to become unthreaded from the boss 18 with the result that the cartridge is displaced downwardly from the plunger 23 to the extent that the plunger may not be efiective to break the seal within the cartridge when the lever 11 is actuated. It is, therefore, desirable that the cartridge neck 20 always be maintained at a predetermined vertical distance from the plunger 23 by some form of locking means. Towards this end, a pair of grooves 35 v are provided in the boss 18, into which may be inserted a generally U-shaped locking pin 36 to fit within an annular key way 37 of the cartridge neck 20. It will be apparent that unless the key way 37 is properly aligned with the grooves 35, the locking pin 36 cannot be fully inserted. Thus, the locking pin 36 not only acts as a means of retaining the cartridge neck 20 at a given distance from the puncture pin 23, but it also serves to assure that in the assembly of cartridge neck 20 within the boss 18 the cartridge must be properly located before the pin 36 may be inserted. As a further precaution, the pin 36 is dimensioned such that if it is not fully inserted into the grooves 35, it will extend outwardly from the boss 18 to the dotted line position, as shown in Figure 1, whereby the head assembly cannot be coupled to the extinguisher tank. In this regard, it is also desirable to provide the pin 36 with a curved portion 38 which will prevent the pin from being removed from the head assembly by coming in contact with the annular shoulder 15, in the event the threaded nut 17 has not been mounted.

A further feature of the present invention for an improved head assembly relates to providing a structure for the puncturing tip of the plunger 23 that will not have a tendency to clog as it is breaking the normal seal or disc within the cartridge neck 20 to effect release of the gas. It will be evident that the distance the plunger 23 enters the cartridge neck will be dependent not only on the spacing of the neck from the plunger, but also upon the degree of actuation of the lever 11. As a result, it has been found that under certain conditions the conventional bore opening 39 at the tip of the plunger, as shown in Figure 3, may become clogged with the particular material it breaks in the eventvthe lever 11 is not actuated fully. To prevent this condition, radially directed apertures 40 and 41 are additionally provided in the lower portion of the plunger 23, whereby regardless of the position of the plunger tip within the neck 20, there will always be a clog-free passage for the gases to escape into the gas tube 33 through the aperture 34.

The operation of this improved extinguisher head assembly is. generally the same as described in connection with applicants above referred to co-pending application, with the important exception that the lever 11 performs the double purpose of acting as a means of actuating the puncturing plunger 23 and also as a means of operating a shut-ofi valve. Thus, at the same time that the plunger 23 is forced downwardly by actuation of the lever 11 to its puncturing position, the valve 24 is also unseated from the valve seat 25, whereby the powder may pass from the powder tube 29, through the inlet chamber 30, and thereafter into the discharge chamber 31 for withdrawal through the discharge hose 32. When the operator desires to shut ofi the extinguisher, he may merely allow the lever 11 to be raised again to its spring biased, normal position, which in turn will cause the valve 24 to again come into sealing contact with the valve seat 25 and close the passage between the inlet chamber 30 and the discharge chamber 31. As a consequence of this novel construction, no shut-ofi valve need be provided in the nozzle of the discharge hose 32 as has been the practice in previous fire extinguisher constructions.

As a result of this improved extinguisher head construction, more simple and convenient means of operating the extinguisher are possible, and at the same time, through the provision of the locking means and clog-free plunger tip, more positive and trouble free operation is assured.

What is claimed is:

1. In a portable, tank type fire extinguisher, operable by puncturing of a gas cartridge contained therein: a head body for connection to said tank, said head body defining an inner passage communicating between an inlet chamber and a discharge chamber; a plunger slidably mounted in said head body for vertical movement from a normal position to a puncturing position to rupture said cartridge; valve means included on said plunger and positioned to close off said passage when said plunger is in said normal position; an operating lever pivotably coupled to said head and positioned for actuation of said plunger to said puncturing position; locking means associated with said head body and adapted for coupling to said cartridge to maintain said cartridge in a given vertical position relative to said plunger; and a puncturing tube on said plunger having radially directed apertures, said puncturing tube being adapted to effect the rupturing of said cartridge.

2. In a portable tank type dry powder fire extinguisher; a head body connected to said tank; a gas cartridge positioned within said tank and having one end coupled to said head body, said head body and said one end defining a gas outlet chamber, said head body further defining. an inner passage communicating between a powder inlet chamber and a powder outlet chamber; a plunger slidably mounted in said head body for vertical movement from a normal position to a puncturing position sealably through said gas outlet chamber to elfect the rupturing of said one end of said cartridge; valve means included, on said plunger and positioned to close oifsaid inner passage when said plunger is in said normal posibody and positioned for actuation of said plunger to said puncturing position; a gas tube communicating between said gas outlet chamber and said tank; and, a powder tube communicating between said powder inlet chamber and said tank.

3. In a portable tank type dry powder fire extinguisher, according to claim 2, a puncturing tube on said plunger having radially directed apertures, said puncturing tube being adapted to efiect the rupturing of said one end of 10 said cartridge.

4. In a portable tank type dry powder fire extinguisher, according to claim 2, locking means associated with said head body and adapted for coupling to said cartridge to maintain said cartridge in a given vertical position rela- 5 tive to said plunger.

References Cited in the file of this patent UNITED STATES PATENTS 2,580,419 Griggs Jan. 1, 1952 2,694,456 Huthsing Nov. 16, 1954 2,778,434 Hastert et a1. Jan. 22, 1957 

